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1 OpenFlow In Depth This document is a result of work by the Network Startup Resource Center (NSRC at and Indiana Center for Network Translational Research and Education (InCNTRE). This document may be freely copied, modified, and otherwise re-used on the condition that any re-use acknowledge the NSRC and InCNTRE as the original sources.

2 These slides contain significant content contributions by

3 Current State of OF Standards OpenFlow 1.3 Supported & Maintained Now up to OpenFlow Latest Spec Release OF-Config 1.2 Available Conformance Testing Full, L2, L3 Profiles Basic Single Table Profile

4 OpenFlow 1.0 to 1.3

5 More Flow Tables 1.0 Single Flow Table 1.3 Allows for multiple Flow Tables o Jump to other tables, but only in a positive direction Includes a group table with multiple group table types Includes meter table for Rate Limiting and QoS

6 Flow Table Types 1.0 Match Fields Priority Counters Actions Timeouts Cookies 1.3 Match Fields Priority Counters Instructions Timeouts Cookies Group Tables Group ID Type Counters Action Buckets Meter Tables Meter Identifier Meter Bands Counters

7 Packet Processing If packet Matches flow table entry, perform Action If packet match flow table entry, look at Instructions Instructions may execute immediate action(s), or Instructions may set actions in the action set Instructions may write to metadata field Instructions may change pipeline processing: o o o Goto table X Goto group table Y Apply meter Z New Data Structure in Pipeline meta data packet Action Set

8 Instructions Instruction Description Required / Optional OFPIT_GOTO_TABLE Jump to table n Required OFPIT_WRITE_METADATA OFPIT_WRITE_ACTIONS Write to Metadata field for use later in pipeline Add Actions(s) to the Action Set for later use Optional Required OFPIT_APPLY_ACTIONS Applies Actions immediately Optional OFPIT_CLEAR_ACTIONS Clears all Actions from Action Set Optional OFPIT_METER Apply meter (rate limiter) Optional OFPIT_EXPERIMENTER (0xFFFF) Experimenter Instructions Optional

9 Required Match Fields (proposed) Match Field Description Pre-requisite OXM_OF_IN_PORT Ingress port None OXM_OF_ETH_DST Ethernet destination address None OXM_OF_ETH_SRC Ethernet source address None OXM_OF_ETH_TYPE Ethernet type of OpenFlow packet payload None OXM_OF_IP_PROTO IPv4 or IPv6 protocol number ETH_TYPE = 0x800 or ETH_TYPE =0x86dd OXM_OF_IPV4_SRC IPv4 source address ETH_TYPE = 0x800 OXM_OF_IPV4_DST IPv4 destination address ETH_TYPE = 0x800 OXM_OF_IPV6_SRC IPv6 source address ETH_TYPE = 0x86dd OXM_OF_IPV6_DST IPv6 destination address ETH_TYPE = 0x86dd OXM_OF_TCP_SRC TCP source port IP_PROTO = 6 OXM_OF_TCP_DST TCP destination port IP_PROTO = 6 OXM_OF_UDP_SRC UDP source port IP_PROTO = 17 OXM_OF_UDP_DST UDP destination port IP_PROTO = 17

10 Optional Match Fields (proposed) Match Field Description Match Field Description OXM_OF_IN_PHY_PORT Physical ingress port OXM_OF_ARP_THA Target L2 Add of ARP payload OXM_OF_METADATA Table metadata OXM_OF_IPV6_FLABEL IPv6 flow label OXM_OF_VLAN_VID VLAN ID OXM_OF_ICMPV6_TYPE ICMPv6 type OXM_OF_VLAN_PCP VLAN PCP OXM_OF_ICMPV6_CODE ICMPv6 code OXM_OF_IP_DSCP Diff Serv Code Point OXM_OF_IPV6_ND_TARGET Target Addr IPv6 Neigh Disc OXM_OF_IP_ECN Ecn bits of the IP header OXM_OF_IPV6_ND_SLL SRC L2 Addr IPv6 Neigh Disc OXM_OF_SCTP_SRC SCTP source port OXM_OF_IPV6_ND_TLL Target L2 Add IPv6 Neigh Disc OXM_OF_SCTP_DST SCTP destaination port OXM_OF_MPLS_LABEL MPLS label OXM_OF_ICMPV4_TYPE ICMP type OXM_OF_MPLS_TC MPLS TC OXM_OF_ICMPV4_CODE ICMP code OXM_OF_MPLS_BOS MPLS BoS bit OXM_OF_ARP_OP ARP opcode OXM_OF_PBB_ISID I-SID in PBB srvc instance tag OXM_OF_ARP_SPA SRC IPv4 Addr of ARP payload OXM_OF_TUNNEL_ID Metadata for a logical port OXM_OF_ARP_TPA Target IPv4 Addr of ARP payload OXM_OF_IPV6_EXTHDR IPv6 extension header field OXM_OF_ARP_SHA SRC Eth Addr of ARP payload

11 1.3 Actions Action OFPAT_OUTPUT Description Output to port - PORT # Physical or Logical switch port # ALL, CONTROLLER, TABLE, IN_PORT Required Reserved Ports - LOCAL, NORMAL, FLOOD Optional Reserved ports OFPAT_COPY_TTL_OUT OFPAT_COPY_TTL_IN OFPAT_SET_MPLS_TTL OFPAT_DEC_MPLS_TTL OFPAT_PUSH_VLAN OFPAT_POP_VLAN OFPAT_PUSH_MPLS OFPAT_POP_MPLS Copy TTL to next outwards header Copy TTL to next inwards header Set MPLS TTL Decrement MPLS TTL Push a new VLAN Tag Pop the outer VLAN Tag Push a new MPLS Tag Pop the outer MPLS Tag

12 More 1.3 Actions Action OFPAT_SET_QUEUE OFPAT_GROUP OFPAT_SET_NW_TTL OFPAT_DEC_NW_TTL OFPAT_SET_FIELD OFPAT_PUSH_PBB OFPAT_POP_PBB OFPAT_EXPERIMENTER OFPAT_DROP Description Set queue id when outputting to a port Apply Group Set IP TTL Decrement IP TTL Set a header field using OXM TLV format Push a new PBB service tag (I-TAG) Pop the outer PBB service tag (I-TAG) 0xffff No explicit drop action

13 1.3 Packet flow through Processing Pipeline

14 1.3 Message Types Symmetric Sent without solicitation in either direction Controller-to-Switch initiated by the controller may or may not require a response from the switch. Asynchronous sent without a controller soliciting them from a switch denote a packet arrival, switch state change, or error

15 1.3 Symmetric OFPT_HELLO OFPT_ERROR OFPT_ECHO_REQUEST OFPT_ECHO_REPLY OFPT_EXPERIMENTER

16 1.3 Controller-to-Switch OFPT_FEATURES_REQUEST OFPT_FEATURES_REPLY OFPT_GET_CONFIG_REQUEST OFPT_GET_CONFIG_REPLY OFPT_SET_CONFIG OFPT_PACKET_OUT OFPT_FLOW_MOD OFPT_GROUP_MOD OFPT_PORT_MOD OFPT_TABLE_MOD

17 1.3 Controller-to-Switch Messages (Cont.) OFPT_MULTIPART_REQUEST OFPT_MULTIPART_REPLY OFPT_BARRIER_REQUEST OFPT_BARRIER_REPLY OFPT_ROLE_REQUEST OFPT_ROLE_REPLY

18 1.3 Asynchronous OFPT_PACKET_IN OFPT_FLOW_REMOVED OFPT_PORT_STATUS

19 Table-miss Specifies how to process the packet that do not match any flows in the flow table. By default, unmatched packets are dropped. Controller can override this behavior. It is identified by match and priority. A flow entry with all wildcard match and priority 0 is a table-miss flow entry. Must at least support sending packet to the controller.

20 1.3 Error Message OFPT_ERROR used to notify controller of a problem Each error message has a type, code and data. Type indicates high-level type of error. Code is interpreted based on the type and points the specific type of problem. Data field contains at least first 64 bytes of the failed request that triggered the error.

21 1.3 Error Examples Request: ofp_flow_mod with invalid outport in action. o Error Type: OFPET_BAD_ACTION. o Error Code: OFPBAC_BAD_OUT_PORT. Request: ofp_flow_mod with invalid match. o Error Type: OFPET_BAD_MATCH. o Error Code : OFPBMC_BAD_TYPE. Request: Match in ofp_flow_mod with missing pre-requisites. o Error Type: OFPET_BAD_MATCH. o Error Code: OFPBMC_BAD_PREREQ.

22 1.3 Group Table Types all - execute each bucket each bucket gets copy of packet flooding, multicast, etc. select - execute one of the buckets in group Based on algorithm defined in switch (e.g. RR) load distribution across span port member links indirect - execute single bucket in group used for next hops and fast convergence fast failover - execute first live bucket (tied to interface)

23 OpenFlow QoS OF 1.0 Optional action "Enqueue" Forwards packet through a queue attached to a port. Header fields can include VLAN priority and IP ToS, so they can be matched against and rewritten. OF 1.3 Stuff from 1.0 New table "Meter Table" Match Fields Priority Counters Instructions Timeouts Timeouts Cooke New instruction Meter meter_id Meter Identifier Meter Bands Counters 32 bit integer used to identify the meter list of meter bands each band specifies rate and behavior

24 1.3 QoS (Cont.) Matching Flow Table Entry Includes instruction: apply Meter ID Remark ToS Collect Stats If band type re-mark? Collect Stats / Determine which Meter Band Applies If band type drop? Drop Packet Collect Stats Meter Identifier Meter Bands Counters Band Type Rate Counters Type Specific Arguments Drop or remark DSCP kb/s burst One or more Meter Bands per Meter Table Entry

25 1.3 QoS (Cont.) DSCP=AF41 Priority Counters Instructions Timeouts Timeouts Cooke Meter Identifier Meter Bands Counters Drop 5Gbs Counters N/A Remark DSCP 2.5Gbs Counters SET DSCP = BE Remark DSCP 1Gbs Counters SET DSCP = AF31 "the meter applies the meter band with the highest configured rate that is lower than the current measured rate"

26 OpenFlow 1.3 Examples and Use Cases S C

27 Addi$onal 1.3 Network Behaviors Tunneling PBB/Mac in Mac Encap/Decap packets QinQ VLAN Stacking Push/Pop/Rewrite MPLS Rou$ng emula$on (TTL decrement) Mul$cast/Broadcast (Group Table) Experimenter Func$ons???

28 VLAN to MPLS Conversion Example

29 HTTP Redirec$on using Extension Example Controller acts as redirector to designated server Match ip_prot = 6 tcp_dst = 80 Extension hup_method to match on hup GET Ac$on Modify ipv4_dst of packet Send out switch port towards designated server

30 Simple Router Example

31 Controller Running Virtual Router App Virtual Interface 1 is on same subnet as Host 1 & 2 and acts as Default Gateway Virtual Interface 2 is on the same subnet as the ISP router

32 Arp Table in the Controller Arp Table in the Controller Virtual Router No. IP MAC Switch DPID Port Action : V-Int : V-Int2 OFPT-PACKET-OUT : AAA Eth1 OFPT-PACKET-OUT : AAA Eth2 OFPT-PACKET-OUT : AAA Eth3

33 Pipeline Table 1: Send to Routing Table or Switching Table Table 2: Match Eth-SRC & DST Output to Port Table 3: Send to Virtual Router Port or Send to correct Group Table Group Tables: Decrement TTL Set ETH SRC Set ETH DST OUTPUT to Port Table 3 Routing Table 2 Switching Port 2 Group Table 1 Port 1 Packet Enters Group Table 1 Table 2 Eth Dst Port 2 Port 1 Group Table 3 Port 3

34 Table 1 (Routing or Switching) Table 1 Ethertype Ethernet-dst Action ==ARP * OFPAT_OUTPUT to CONTROLLER * : OFPIT_GOTO_TABLE 2 (Routing) * : OFPIT_GOTO_TABLE 2 (Routing) * * OFPIT_GOTO_TABLE 3 (Switching) If ARP Packet, send to the controller. If MAC DST is a Virtual Router Interface, Send to the Routing Table. Otherwise, send to Switching Table

35 Switching Table Table 2 (Switching) Eth-SRC Eth-DST Action : : OFPAT_OUTPUT to Eth : : OFPAT_OUTPUT to Eth 1 If Eth-SRC is Host 1 and Eth-DST is Host 2, send out Port Eth 2 If Eth-SRC is Host 2 and Eth-DST is Host 1, send out Port Eth 1

36 Routing Table Table 3 (Routing) IP-SRC IP-DST Action * OFPAT_OUTPUT to LOCAL * OFPAT_OUTPUT to LOCAL * OFPAT_GROUP 1 * OFPAT_GROUP 2 * OFPAT_GROUP 3 If IP-DST is to a Virtual Router Interface, send to the local (switch) stack. If IP-DST is to Host 1 send to Group Table 1 If IP-DST is to Host 2 send to Group Table 2 If IP-DST is to Internet Gateway send to Group Table 3

37 Group Tables Group Table 1 No. Action Value 1 OFPAT_DEC_NW_TTL - 2 OFPAT_SET_FIELD OXM_OF_ETH_SRC 3 OFPAT_SET_FIELD OXM_OF_ETH_DST : (V-Int 1) : (Host 1) 4 OFPAT_OUTPUT Eth 1 1) Decrement IP TTL 2) Set ETH SRC to Virtual Router Interface 1 3) Set ETH DST to Host 1 4) OUTPUT to Port Eth 1

38 Group Tables (Cont) Group Table 2 No. Action Value 1 OFPAT_DEC_NW_TTL - 2 OFPAT_SET_FIELD OXM_OF_ETH_SRC 3 OFPAT_SET_FIELD OXM_OF_ETH_DST : (V-Int 1) : (Host 2) 4 OFPAT_OUTPUT Eth 2 Group Table 3 No. Action Value 1 OFPAT_DEC_NW_TTL - 2 OFPAT_SET_FIELD OXM_OF_ETH_SRC 3 OFPAT_SET_FIELD OXM_OF_ETH_DST : (V-Int 2) : (ISP GW) 4 OFPAT_OUTPUT Eth 3

39 Multi-Table Exercise